if the ratio of boys to girls is 3/4 and there are 49 students how many boys are there?
3/7 = x/49
Cross multiply and solve for x.
75
Does 75 make sense? There are only a total of 49 students.
This site explains how to solve a problem with a proportion.
http://www.aaamath.com/rat-prop-crossx.htm
21
To find the number of boys, you will need to determine the fraction of boys in the total number of students and then multiply it by the total number of students.
Step 1: Determine the fraction of boys in the total number of students.
Since the ratio of boys to girls is 3/4, the fraction of boys is 3/(3+4) = 3/7 (denominator is the sum of the ratio).
Step 2: Multiply the fraction of boys by the total number of students.
Multiply 3/7 by the total number of students, which is 49.
(3/7) * 49 = 21.
Therefore, there are 21 boys.